Swedish Company Tackles Child Abuse Images

Child sexual abuse images are a heinous problem on the internet which have persisted despite years of effort to purge them. Now a Swedish company is offering an innovative approach that can match any image against a database of known child pornography regardless of the source of the image, or if the computer is online.

NetClean’s approach is based on image recognition, but differs from previous image-based pornography filters. Early attempts used AI to try to discern the contents of an image, typically looking for certain outlines and tonal values. Such approaches are unable to discern between legitimate pictures, e.g. a nude, and pornography.

Other attempts include blocking sites by IP address or domain name. These are not particularly effective as pedophile trades often take place either across peer-to-peer networks, or via IRC chatrooms that are open for a few hours only and then disappear.

According to NetClean’s founder, Pelle Garå, their approach is based on capturing the existing knowledge that police forces have, and automating the process.

“Police forces have to decide whether an image features abuse or not. A trained officer makes that decision, not us. What our system does is to take those images that have been identified and then match any other picture against them.”

Taking the police database, NetClean’s algorithm analyses the images it contains and creates an encrypted hash of each image of abuse. That hash is then added to the NetClean program. When installed on a client’s computer, the program scans every image viewed on that computer, regardless of where it comes from, using the same algorithm. If the hash it generates matches one stored in the database of known images of abuse, it automatically generates an alert. It is then up to the company as to how they deal with the case.

“We have no false positives,” claims Mr. Garå. “If the system generates a match it means it is a known image of abuse and is illegal.”

By only matching against known abuse images, NetClean avoids the concern that many parents have that innocent pictures of their children, say on a beach or at bath time, may be construed as pornographic.

The system has proved popular in Sweden, where some 400,000 licenses have been sold to date. Mr. Garå says companies install the software on corporate machines in much the same way as anti-virus software. The cost is around £20 per year for a small company, which is cut to about £5 per license for large companies.

“Companies want to do this for insurance issues, to protect their brand, or for issues relating to CSR,” he said.

According to police figures, approximately 0.5% of all internet users will attempt to access images of child abuse at some time. Worryingly about a third of people who collect such images will go on to become abusers themselves.

Mr. Garå, says the company, which has strong links with the police across the Nordic countries, is expanding out into the rest of Europe and especially the U.K.

Comments (3 of 3)

Howdy! This post couldn't be written any better! Reading this post reminds me of my good old room mate! He always kept chatting about this. I will forward this write-up to him. Pretty sure he will have a good read. Thank you for sharing!

7:18 am April 2, 2011

Cybercriminal wrote:

The article doesn't say what will happen once the images are identified.

The Danish police use this technology. They use it to implement a very technically flawed "blocking" system which they use instead of real action against the crimes. Indeed, police officer Lars Underbjerg from the Danish police even told the German Parliament they don't even pass on reports of this illegal content to the USA or Russia, because they probably wouldn't care! The text is only in German (www.bundestag.de/bundestag/.../Stellungnahme_Underbjerg_deutsch.pdf)

5:58 pm April 1, 2011

johnny wrote:

wow

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